diff --git a/frontend/lib/pages/player_page.dart b/frontend/lib/pages/player_page.dart
index 83f327b..15dd36e 100644
--- a/frontend/lib/pages/player_page.dart
+++ b/frontend/lib/pages/player_page.dart
@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -30,14 +32,17 @@ class _PlayerPageState extends State<PlayerPage> {
   final ChatService _chatService = ChatService();
   final TextEditingController _msgController = TextEditingController();
   final List<ChatMessage> _messages = [];
-  final List<Widget> _danmakus = [];
+  final List<_DanmakuEntry> _danmakus = [];
 
   bool _isError = false;
   String? _errorMessage;
   bool _showDanmaku = true;
   bool _isRefreshing = false;
   bool _isFullscreen = false;
+  bool _controlsVisible = true;
   int _playerVersion = 0;
+  String _selectedResolution = 'Source';
+  Timer? _controlsHideTimer;
 
   @override
   void initState() {
@@ -46,6 +51,7 @@ class _PlayerPageState extends State<PlayerPage> {
       _initializePlayer();
     }
     _initializeChat();
+    _showControls();
   }
 
   Future<void> _initializePlayer() async {
@@ -99,18 +105,23 @@ class _PlayerPageState extends State<PlayerPage> {
 
   void _addDanmaku(String text) {
     final key = UniqueKey();
-    final top = 20.0 + (DateTime.now().millisecondsSinceEpoch % 6) * 30.0;
+    final lane = DateTime.now().millisecondsSinceEpoch % 8;
+    final topFactor = 0.06 + lane * 0.045;
 
-    final danmaku = _DanmakuItem(
-      key: key,
-      text: text,
-      top: top,
-      onFinished: () {
-        if (mounted) setState(() => _danmakus.removeWhere((w) => w.key == key));
-      },
-    );
-
-    setState(() => _danmakus.add(danmaku));
+    setState(() {
+      _danmakus.add(
+        _DanmakuEntry(
+          key: key,
+          text: text,
+          topFactor: topFactor,
+          onFinished: () {
+            if (mounted) {
+              setState(() => _danmakus.removeWhere((w) => w.key == key));
+            }
+          },
+        ),
+      );
+    });
   }
 
   void _sendMsg() {
@@ -137,6 +148,7 @@ class _PlayerPageState extends State<PlayerPage> {
       _danmakus.clear();
       _playerVersion++;
     });
+    _showControls();
 
     if (kIsWeb) {
       await Future<void>.delayed(const Duration(milliseconds: 150));
@@ -175,6 +187,7 @@ class _PlayerPageState extends State<PlayerPage> {
     if (mounted) {
       setState(() => _isFullscreen = nextValue);
     }
+    _showControls();
   }
 
   void _toggleDanmaku() {
@@ -184,6 +197,74 @@ class _PlayerPageState extends State<PlayerPage> {
         _danmakus.clear();
       }
     });
+    _showControls();
+  }
+
+  void _showControls() {
+    _controlsHideTimer?.cancel();
+    if (mounted) {
+      setState(() => _controlsVisible = true);
+    }
+    _controlsHideTimer = Timer(const Duration(seconds: 3), () {
+      if (mounted) {
+        setState(() => _controlsVisible = false);
+      }
+    });
+  }
+
+  void _toggleControlsVisibility() {
+    if (_controlsVisible) {
+      _controlsHideTimer?.cancel();
+      setState(() => _controlsVisible = false);
+    } else {
+      _showControls();
+    }
+  }
+
+  Future<void> _selectResolution() async {
+    _showControls();
+    final nextResolution = await showModalBottomSheet<String>(
+      context: context,
+      builder: (context) {
+        const options = ['Source', '720p', '480p'];
+        return SafeArea(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              const ListTile(
+                title: Text('Playback Resolution'),
+                subtitle: Text(
+                  'Current backend only provides the source stream. Lower resolutions are reserved for future multi-bitrate output.',
+                ),
+              ),
+              ...options.map((option) {
+                final enabled = option == 'Source';
+                return ListTile(
+                  enabled: enabled,
+                  leading: Icon(
+                    option == _selectedResolution
+                        ? Icons.radio_button_checked
+                        : Icons.radio_button_off,
+                  ),
+                  title: Text(option),
+                  subtitle: enabled
+                      ? const Text('Available now')
+                      : const Text('Requires backend transcoding support'),
+                  onTap: enabled ? () => Navigator.pop(context, option) : null,
+                );
+              }),
+            ],
+          ),
+        );
+      },
+    );
+
+    if (nextResolution == null || nextResolution == _selectedResolution) {
+      return;
+    }
+
+    setState(() => _selectedResolution = nextResolution);
+    await _refreshPlayer();
   }
 
   @override
@@ -192,6 +273,7 @@ class _PlayerPageState extends State<PlayerPage> {
       SystemChrome.setEnabledSystemUIMode(SystemUiMode.edgeToEdge);
       SystemChrome.setPreferredOrientations(DeviceOrientation.values);
     }
+    _controlsHideTimer?.cancel();
     _controller?.dispose();
     _chatService.dispose();
     _msgController.dispose();
@@ -203,11 +285,22 @@ class _PlayerPageState extends State<PlayerPage> {
     bool isWide = MediaQuery.of(context).size.width > 900;
 
     return Scaffold(
-      appBar: AppBar(title: Text(widget.title)),
-      body: isWide ? _buildWideLayout() : _buildMobileLayout(),
+      backgroundColor: _isFullscreen
+          ? Colors.black
+          : Theme.of(context).colorScheme.surface,
+      appBar: _isFullscreen ? null : AppBar(title: Text(widget.title)),
+      body: _isFullscreen
+          ? _buildFullscreenLayout()
+          : isWide
+          ? _buildWideLayout()
+          : _buildMobileLayout(),
     );
   }
 
+  Widget _buildFullscreenLayout() {
+    return SizedBox.expand(child: _buildVideoPanel());
+  }
+
   // 宽屏布局：左右分栏
   Widget _buildWideLayout() {
     return Row(
@@ -244,96 +337,179 @@ class _PlayerPageState extends State<PlayerPage> {
   }
 
   Widget _buildVideoPanel() {
-    return Container(
-      color: Colors.black,
-      child: Column(
-        children: [
-          Expanded(child: _buildVideoWithDanmaku()),
-          _buildPlaybackControls(),
-        ],
+    return MouseRegion(
+      onHover: (_) => _showControls(),
+      onEnter: (_) => _showControls(),
+      child: GestureDetector(
+        behavior: HitTestBehavior.opaque,
+        onTap: _toggleControlsVisibility,
+        onDoubleTap: _toggleFullscreen,
+        child: Container(
+          color: Colors.black,
+          child: Stack(
+            children: [
+              Positioned.fill(child: _buildVideoWithDanmaku()),
+              Positioned(
+                left: 0,
+                right: 0,
+                bottom: 0,
+                child: _buildPlaybackControls(),
+              ),
+            ],
+          ),
+        ),
       ),
     );
   }
 
   Widget _buildVideoWithDanmaku() {
-    return Stack(
-      children: [
-        Center(
-          child: _isError
-              ? Text(
-                  "Error: $_errorMessage",
-                  style: TextStyle(color: Colors.white),
-                )
-              : kIsWeb
-              ? WebStreamPlayer(
-                  key: ValueKey('web-player-$_playerVersion'),
-                  streamUrl: widget.playbackUrl,
-                )
-              : _controller != null && _controller!.value.isInitialized
-              ? AspectRatio(
-                  aspectRatio: _controller!.value.aspectRatio,
-                  child: VideoPlayer(_controller!),
-                )
-              : CircularProgressIndicator(),
-        ),
-        if (_showDanmaku) ClipRect(child: Stack(children: _danmakus)),
-        if (_isRefreshing)
-          const Positioned(
-            top: 16,
-            right: 16,
-            child: SizedBox(
-              width: 24,
-              height: 24,
-              child: CircularProgressIndicator(strokeWidth: 2),
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        return Stack(
+          children: [
+            Center(
+              child: _isError
+                  ? Text(
+                      "Error: $_errorMessage",
+                      style: TextStyle(color: Colors.white),
+                    )
+                  : kIsWeb
+                  ? WebStreamPlayer(
+                      key: ValueKey('web-player-$_playerVersion'),
+                      streamUrl: widget.playbackUrl,
+                    )
+                  : _controller != null && _controller!.value.isInitialized
+                  ? AspectRatio(
+                      aspectRatio: _controller!.value.aspectRatio,
+                      child: VideoPlayer(_controller!),
+                    )
+                  : CircularProgressIndicator(),
             ),
+            if (_showDanmaku)
+              ClipRect(
+                child: Stack(
+                  children: _danmakus
+                      .map(
+                        (item) => _DanmakuItem(
+                          key: item.key,
+                          text: item.text,
+                          topFactor: item.topFactor,
+                          containerWidth: constraints.maxWidth,
+                          containerHeight: constraints.maxHeight,
+                          onFinished: item.onFinished,
+                        ),
+                      )
+                      .toList(),
+                ),
+              ),
+            if (_isRefreshing)
+              const Positioned(
+                top: 16,
+                right: 16,
+                child: SizedBox(
+                  width: 24,
+                  height: 24,
+                  child: CircularProgressIndicator(strokeWidth: 2),
+                ),
+              ),
+          ],
+        );
+      },
+    );
+  }
+
+  Color _usernameColor(String username, String type) {
+    if (type == "system") {
+      return Colors.blue;
+    }
+    final normalized = username.trim().toLowerCase();
+    var hash = 5381;
+    for (final codeUnit in normalized.codeUnits) {
+      hash = ((hash << 5) + hash) ^ codeUnit;
+    }
+    final hue = (hash.abs() % 360).toDouble();
+    return HSLColor.fromAHSL(1, hue, 0.72, 0.68).toColor();
+  }
+
+  Widget _buildMessageItem(ChatMessage message) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 4.0),
+      child: RichText(
+        text: TextSpan(
+          style: TextStyle(
+            color: Theme.of(context).textTheme.bodyMedium?.color,
           ),
-      ],
+          children: [
+            TextSpan(
+              text: "${message.username}: ",
+              style: TextStyle(
+                fontWeight: FontWeight.bold,
+                color: _usernameColor(message.username, message.type),
+              ),
+            ),
+            TextSpan(text: message.content),
+          ],
+        ),
+      ),
     );
   }
 
   Widget _buildPlaybackControls() {
-    return Container(
-      width: double.infinity,
-      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
-      decoration: BoxDecoration(
-        color: Colors.black.withValues(alpha: 0.92),
-        border: Border(
-          top: BorderSide(color: Colors.white.withValues(alpha: 0.08)),
-        ),
-      ),
-      child: Wrap(
-        spacing: 10,
-        runSpacing: 10,
-        children: [
-          _buildControlButton(
-            icon: Icons.refresh,
-            label: "Refresh",
-            onPressed: _refreshPlayer,
+    return IgnorePointer(
+      ignoring: !_controlsVisible,
+      child: AnimatedOpacity(
+        opacity: _controlsVisible ? 1 : 0,
+        duration: const Duration(milliseconds: 220),
+        child: Container(
+          width: double.infinity,
+          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
+          decoration: BoxDecoration(
+            gradient: LinearGradient(
+              begin: Alignment.bottomCenter,
+              end: Alignment.topCenter,
+              colors: [
+                Colors.black.withValues(alpha: 0.9),
+                Colors.black.withValues(alpha: 0.55),
+                Colors.transparent,
+              ],
+            ),
           ),
-          _buildControlButton(
-            icon: _showDanmaku ? Icons.subtitles : Icons.subtitles_off,
-            label: _showDanmaku ? "Danmaku On" : "Danmaku Off",
-            onPressed: _toggleDanmaku,
-          ),
-          _buildControlButton(
-            icon: _isFullscreen ? Icons.fullscreen_exit : Icons.fullscreen,
-            label: _isFullscreen ? "Exit Fullscreen" : "Fullscreen",
-            onPressed: _toggleFullscreen,
-          ),
-          _buildControlButton(
-            icon: Icons.high_quality,
-            label: "Resolution",
-            onPressed: () {
-              ScaffoldMessenger.of(context).showSnackBar(
-                const SnackBar(
-                  content: Text(
-                    "Resolution switching is planned for a later update.",
+          child: SafeArea(
+            top: false,
+            child: Align(
+              alignment: Alignment.bottomCenter,
+              child: Wrap(
+                spacing: 10,
+                runSpacing: 10,
+                alignment: WrapAlignment.center,
+                children: [
+                  _buildControlButton(
+                    icon: Icons.refresh,
+                    label: "Refresh",
+                    onPressed: _refreshPlayer,
                   ),
-                ),
-              );
-            },
+                  _buildControlButton(
+                    icon: _showDanmaku ? Icons.subtitles : Icons.subtitles_off,
+                    label: _showDanmaku ? "Danmaku On" : "Danmaku Off",
+                    onPressed: _toggleDanmaku,
+                  ),
+                  _buildControlButton(
+                    icon: _isFullscreen
+                        ? Icons.fullscreen_exit
+                        : Icons.fullscreen,
+                    label: _isFullscreen ? "Exit Fullscreen" : "Fullscreen",
+                    onPressed: _toggleFullscreen,
+                  ),
+                  _buildControlButton(
+                    icon: Icons.high_quality,
+                    label: _selectedResolution,
+                    onPressed: _selectResolution,
+                  ),
+                ],
+              ),
+            ),
           ),
-        ],
+        ),
       ),
     );
   }
@@ -341,10 +517,13 @@ class _PlayerPageState extends State<PlayerPage> {
   Widget _buildControlButton({
     required IconData icon,
     required String label,
-    required VoidCallback onPressed,
+    required FutureOr<void> Function() onPressed,
   }) {
     return FilledButton.tonalIcon(
-      onPressed: onPressed,
+      onPressed: () async {
+        _showControls();
+        await onPressed();
+      },
       icon: Icon(icon, size: 18),
       label: Text(label),
       style: FilledButton.styleFrom(
@@ -376,28 +555,7 @@ class _PlayerPageState extends State<PlayerPage> {
             itemCount: _messages.length,
             itemBuilder: (context, index) {
               final m = _messages[index];
-              return Padding(
-                padding: const EdgeInsets.symmetric(vertical: 4.0),
-                child: RichText(
-                  text: TextSpan(
-                    style: TextStyle(
-                      color: Theme.of(context).textTheme.bodyMedium?.color,
-                    ),
-                    children: [
-                      TextSpan(
-                        text: "${m.username}: ",
-                        style: TextStyle(
-                          fontWeight: FontWeight.bold,
-                          color: m.type == "system"
-                              ? Colors.blue
-                              : Theme.of(context).colorScheme.primary,
-                        ),
-                      ),
-                      TextSpan(text: m.content),
-                    ],
-                  ),
-                ),
-              );
+              return _buildMessageItem(m);
             },
           ),
         ),
@@ -437,15 +595,33 @@ class _PlayerPageState extends State<PlayerPage> {
   }
 }
 
+class _DanmakuEntry {
+  final Key key;
+  final String text;
+  final double topFactor;
+  final VoidCallback onFinished;
+
+  const _DanmakuEntry({
+    required this.key,
+    required this.text,
+    required this.topFactor,
+    required this.onFinished,
+  });
+}
+
 class _DanmakuItem extends StatefulWidget {
   final String text;
-  final double top;
+  final double topFactor;
+  final double containerWidth;
+  final double containerHeight;
   final VoidCallback onFinished;
 
   const _DanmakuItem({
     super.key,
     required this.text,
-    required this.top,
+    required this.topFactor,
+    required this.containerWidth,
+    required this.containerHeight,
     required this.onFinished,
   });
 
@@ -487,9 +663,8 @@ class __DanmakuItemState extends State<_DanmakuItem>
       animation: _animation,
       builder: (context, child) {
         return Positioned(
-          top: widget.top,
-          // left 使用 MediaQuery 获取屏幕宽度进行动态计算
-          left: MediaQuery.of(context).size.width * _animation.value,
+          top: widget.containerHeight * widget.topFactor,
+          left: widget.containerWidth * _animation.value,
           child: Text(
             widget.text,
             style: TextStyle(
diff --git a/frontend/pubspec.yaml b/frontend/pubspec.yaml
index c731046..1ad5034 100644
--- a/frontend/pubspec.yaml
+++ b/frontend/pubspec.yaml
@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.0-beta3.7
+version: 1.0.0-beta4.1
 
 environment:
   sdk: ^3.11.1